missing field in grib output

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alainF
Posts: 37
Joined: Fri Apr 19, 2019 8:12 am

missing field in grib output

Post by alainF » Fri Oct 16, 2020 10:20 am

Hello,
I use UPPV3.2 to post process the wrfout files coming from my simulation (WRF4.2).
I want to output the wind gusts values at 10m above ground. In did not find the output by using the standard wrf.cntrl.parm file. So I have opened this file and set 1 for the field MAX WIND HGHT LEVEL, and also for MAX 10m WIND SPEED (see attached file).
Then, I run again unipost, but when I look at the fields inside the generated grib file (with panoply), I don't see any max wind field.
How can I activate this output ?

Thank you,
Attachments
wrf_cntrl.parm.txt
(30.56 KiB) Downloaded 18 times

hertneky
Posts: 63
Joined: Tue May 12, 2020 4:18 pm

Re: missing field in grib output

Post by hertneky » Fri Oct 16, 2020 8:51 pm

Hello,

For the 'MAX 10m WIND SPEED' variable, UPP reads in the field 'WSPD10MAX' from your WRF output file. If this field is not present in your wrfout or if it is zero-filled, then UPP would not output it in your grib file. Can you check that this field is being output by WRF and that it is not zero-filled?

'MAX WIND HGHT LEVEL' is the height of maximum wind and does not effect the output of the 'MAX 10m WIND SPEED'. Are you wanting this variable output as well? It is computed in UPP using the subroutine mxwind which is available in UPPV3.2/src/unipost/GFSPOST.f (search mxwind in that routine). The input for this subroutine are pressure, u/v-wind, temperature, and height. The output for this variable would show as 'HGT' in your grib output with the level defined as something like 'max wind'. If you were also wanting this variable and you don't see it, then let me know.

~UPP-Help~

alainF
Posts: 37
Joined: Fri Apr 19, 2019 8:12 am

Re: missing field in grib output

Post by alainF » Sat Oct 17, 2020 7:34 am

Thank you for your answer,
I want the 10m max wind speed.
I typed "ncdump -h wrfout_d01_2020-10-17_02:00:00 |grep WSPD10MAX" and no answer. So I assume that my WRF does not produce that field.
How can I change that ?
Thank you,

hertneky
Posts: 63
Joined: Tue May 12, 2020 4:18 pm

Re: missing field in grib output

Post by hertneky » Mon Oct 19, 2020 3:12 pm

That's right, If it is not in your wrfout, then WRF isn't outputting it. It would be best to ask the WRF team about outputting this. You want to make sure that this is turned on in your WRF registry. For example, in your WRF/Registry/Registry.EM_COMMON, the IO column (8th column) needs to have the history turned on with an 'h' for the WSPD10MAX variable. Ability to output might also depend on your model configuration (physics used, etc). The WRF team would be able to help more than I can, since I don't work with or run the WRF model myself.

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